Final answer:
The tumor that arises from the sheath of Schwann cells in the peripheral portion of cranial nerve VIII is called an acoustic neuroma or vestibular schwannoma.
Step-by-step explanation:
The tumor that arises from the sheath of Schwann cells in the peripheral portion of cranial nerve VIII is called an acoustic neuroma or vestibular schwannoma.
These tumors are usually benign and originate from the Schwann cells that wrap around the vestibular division of cranial nerve VIII, also known as the cochlear nerve or auditory nerve. The vestibular division is responsible for transmitting balance and spatial information.
Acoustic neuromas can cause symptoms such as hearing loss, tinnitus (ringing in the ears), vertigo, and balance problems.